The overarching goal of this project is to move a new, dry powder formulation of Hepatitis-B vaccine on its path to commercialization. In the Phase I SBIR we tested in vitro three Hep-B dry powder formulations of commercially available Shanvac-B and demonstrated powder stability and immunogenicity at temperatures ranging from -20 ?C through 65 oC. At these temperature extremes the currently marketed liquid Hepatis B vaccine is inactivated as the HBsAg antigen separates from the alum adjuvant. Our studies also showed that the dry micro-scale powders dissolved very rapidly, suggesting their utility in single dose auto-reconstitution devices aimed at parenteral administration. These results have far-reaching implications in regard to vaccine storage, transport and administration, especially in developing countries where limited refrigeration and electric power and high ambient temperatures restrict the useful life and potency of liquid vaccines. In the proposed Phase II SBIR study, we will choose the optimum formulation from the three that we developed earlier and pair this powder with a single dose auto-reconstitution device being developed by Becton Dickinson (BD). The drug- device combination will be used to assess potency in a mouse model compared to a control group of animals that will be administered Shanvac-B by needle and syringe. Potency will be assessed from ELISA analysis of animal sera. . The outcome of the Phase II work will be judged based on the potency of the Hep-B dry powder formulation and the functionality and performance of the BD device as compared with the potency of the needle and syringe administration.